Abhishek Majumdar writes plays that rattle people. His trilogy on the Kashmir crisis – one of which, The Djinns of Eidgah, was staged at London’s Royal Court in 2013 – sparked much sound and fury. So did Salvation House, three years later, in which he wrote damningly about the ancient roots of Hindutva, rightwing nationalism in India.

Majumdar has been hauled into police stations over the years and followed by shadowy figures he suspects to be government officials. Just a few weeks ago, a staging of The Djinns of Eidgah was halted by the authorities in Jaipur. He believes his phone to be tapped and his emails monitored.

Too much for Jaipur … The Djinns Of Eidgah at the Royal Court in 2013. Photograph: Tristram Kenton/The Guardian

Majumdar, who lives in Bangalore, eventually won the right to his freedom of expression. The theatre issued an apology to the Tibetan community, he explains, sitting in the venue’s cafe, and it is now about to stage Pah-La. “The leadership at the Royal Court was extraordinary in accepting problems that were larger than them and then doing something about it.”

The play will still, surely, ruffle some feathers. Set among a monastic circle of Tibetans, the drama shows their forced assimilation and interrogation at the hands of the Chinese army, but it also dramatises the controversial practise of self-immolation among Tibetan protestors (a woman sets herself alight in his play), and the faultlines between non-violent Buddhist ideals and the all-too-human descent into retaliatory violence that the 2008 riots encapsulated.

So many Kashmir boys lost their lives because they had a gun. A gun changes a person

The idea for the play came to him soon after finishing his Kashmir trilogy. “I witnessed a lot of violence in Kashmir. So many boys lost their lives because they had a gun. A gun changes a person. It made me wonder, ‘If this is revolution, what happens after it?’”

That led him to explore the themes at the heart of Pah-La. “In the last century, there were so many major examples of non-violent revolutions, from Gandhi’s to Martin Luther King’s to Nelson Mandela’s. But if these are models to go by, what happened to them? They vanished after the 1970s.”

Tibet, he says, is the last remaining model for such non-violence. “The Tibetans are at the forefront of a conscience that the world needs to have. When the last Tibetan turns violent, we should pack up.”

Perhaps unusually for a playwright, Majumdar, 38, comes from a science background and his research is often infused by a scientist’s rigour. He initially read maths and physics at Delhi university and carried on studying. He did a course on rural development “because I wanted to understand how villages worked”. After that, it was management, and then he was going to study environmental economics on a scholarship at Cambridge (“I got deeply interested in forest issues”), but accepted a theatre scholarship instead. “I didn’t want to leave university,” he says, and likens the research he undertakes for each play to completing a “mini MPhil”.

For Pah-La, he began by reading about Tibetan Buddhism in Bengali (which is similar to the scriptural language, Pali) and about Chinese communism, before talking to Tibetans. “I taught voluntary English classes in India first of all. I had some students who were monks. Then I managed to crack through to Chinese chatrooms and servers to talk with people in Tibet.”

I’m under surveillance in Delhi. If I send an email to someone in Tibet today, it’ll reach them the day after tomorrow

His play features polygraph tests used on Tibetan prisoners. For this, he discovered sites where Mainland China traded in electrical equipment: “I figured that a lot of polygraph machines were sold to Tibet around 2008, so I got in touch with people from the Hong Kong police and went into sites asking for quotes to buy the machines.”

Majumdar’s processes sound more like those of a detective or an investigative reporter than a writer observing the world from a garret. For his Kashmir plays, he spent time in police bunkers and the dens of militants. For Pah-La, he decided he had to go to Lhasa, whatever the cost.

While there, he and his wife Pallavi, a painter, traced part of the journey that Tibetans used to escape into exile. “One has to walk at night across the Himalayas, hiding from the Chinese soldiers.” He is reluctant to give many more details, quipping: “That’s another play!”

Rehearsals for Pah-La at the Royal Court, London. Photograph: Helen Murray

He was given an official guide on his arrival to Lhasa, who accompanied him wherever he went. “My work would start after the guide had left me at 8pm. I went into prisons with people who were taking in food. There were Chinese bars and Tibetan ones. I went to both. The things I found out were extraordinary. People can’t even say the Dalai Lama’s name in Tibet. You can be put in prison for saying, ‘His Holiness the Dalai Lama.’ So they said ‘HH’ for fear of being arrested.”

Majumdar recorded the phone numbers of his sources in a secret code and created maps that would not implicate those he spoke to in Lhasa. Yet he felt himself being watched when he returned to India. “I’m under an enormous amount of surveillance in Delhi. If I send an email to someone in Tibet today, it’ll reach them the day after tomorrow.”

He has learned not to let it affect him too much, he says. “I’ve grown used to it. There was a guy who approached me in Delhi out of the blue.” He thinks he was from some Chinese agency. “They knew I had gone into prisons [in Lhasa] and other things like that. The guy spoke in Hindi except for one phrase in English, when he said, ‘Accidents happen in foreign countries.’”

Given that Majumdar was just about to travel abroad, he took it as a barely veiled threat on his life. How did he respond? By switching back to Hindi and asking the man: “Ice-cream khao ge?” (“Would you like some ice-cream?”) He shrugs. “What other response can you have to a comment like that?”

If this was a low point, one of the highs came at an audience with the Dalai Lama. He was supposed to have 10 minutes, but the Dalai Lama was so engaged by the issues of Majumdar’s play that their meeting stretched to an hour. “We spoke about many things. He told me to write fearlessly.”

Majumdar is working on a new play, called Baatin, that looks at the multiple meanings of the Qur’an – to highlight its plurality and challenge the notion that Islam is a religion of violence. When it began as a faith, he says, “there were a few Arab men and women. If I had said at the time that I’d seen a terrorist, everyone would think I was talking about a Christian.”

His research so far has taken him to Al-Azhar University, the centre for Islamic intellectual study in Cairo. He is not under any illusions about the difficulties of staging such politically charged material. “Right now,” he says, “nobody wants to touch it.”